Posted by **Alonzo** on Thursday, March 11, 2010 at 1:47pm.

Rosea drives her car 30 kilometers to the train station, where she boards a train to complete her trip. The total trip is 120 kilometers. The average speed of the train is 20 kilometers per hour faster than that of the car. At what speed must she drive her car if the total time for the trip is less than 2.5 hours?

- Precalculus -
**FredR**, Thursday, March 11, 2010 at 8:09pm
distance = velocity x time or

time = distance / velocity

total time=d1/v1+d2/v2=2.5 hrs (1)

where d1 = car distance = 30 (2)

v1 = car speed

d2 = train distance = 120 - d1 (3)

v2 = train velocity = v1+20 (4)

combine (1), (2), (3), and (4) and solve for v1

- elementary -
**Anonymous**, Thursday, March 10, 2011 at 7:34pm
300 and 200000

- Precalculus -
**laura**, Saturday, December 3, 2011 at 3:57pm
idk can you show me how please

## Answer This Question

## Related Questions

- Physics - In the design of a rapid transit system, it is necessary to balance ...
- MATH - Andrea made a car trip of 440 Kilometers. She averaged 54 Kilometers per ...
- math - Andrea made a car trip of 440 Kilometers. She averaged 54 Kilometers per ...
- Algebra - Is there an easier way to do this? "A freight train leaves a station ...
- physics - In the design of a rapid transit system, it is necessary to balance ...
- physics - In the design of a rapid transit system, it is necessary to balance ...
- Math - a woman drives to work and averages 70 kilometers per hour for the trip. ...
- math - Phil is making a 40-kilometer canoe trip. If he travels at 30 kilometers ...
- math - Phil is making a 40-kilometer canoe trip. If he travels at 30 kilometers ...
- math - Phil is making a 40-kilometer canoe trip. If he travels at 30 kilometers ...

More Related Questions